Same old question gets asked about 3 times a day!
I suspect that register_globals is set to OFF in your PHP.ini. You could switch that back on, OR you should reference variables passed in the URL like so
<? echo("Test is : ". $_GET['test']); ?>
Incidentally, if your variables are passed from a form using METHOD=POST, you can get at those variables using:
<? echo("Test is : ". $_POST['test']); ?>